Over the last four years, the lowest since march 2008, just before the recession began. To a consumer alert thi evening to a scam spreading across the country. Abc's senior justice correspondent pierre thomas takes us inside the scheme, scammers promising a treasure chest of sweepstakes and lottery winnings and stealing more than one billion dollars from americans. Reporter: We all know the ads. You've won! Reporter: But now jamaican scammers are using the good name of publishers clearing house and other major prize companies to dupe thousands of senior citizens out of their life savings. Kim nichol said her 77-year-old father was ripped off. He received a phone call from someone saying they were from publishers clearing house. They said he won a mercedes, a nice car, and over a million dollars. Reporter: But publishers clearing house had nothing to do with any of this, and it doesn't notify winners over the phone. Kim's father started getting a flood of phone calls from jamaica's 876 area code, with crooks impersonating lottery and government officials, demanding "tax money" before he could get the prize. How much money did your father end up giving? He lost over $85,000. Reporter:85,000? 85,000. It's devastating. Reporter: Listen to this. A sad exchange between a scammer and a womaned named bea who's already shelled out more than $60,000. You have to pay the tax on check before the check could be cashed. You keep asking for more money, more money. Last night I went to bed crying. The bills are coming. I don't have any oil. I'm freezing in here. It's getting cold now. You have to take care of the final payment, bea. Just keep your trust in us now. Reporter: And if the victims don't pay, the scammers are not above threats. There's nothing these scammers won't do. They're absolutely despicable. We want to put out the red flags of warning -- you are Reporter: So how do you protect yourself? If prize officials tell you to pay taxes before they give the money, it's a scam. You always tell us the same, pierre thomas on it again in washington. Pierre, thank you.

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